Fixing ORA-12519 TNS: No Appropriate Service Handler Found Error

Oracle Database is a large and complex system. ORA-12519 Error is a frustrating “TNS No Appropriate Service Handler Found” error in Oracle Database that can be troublesome to debug. It can be caused by a variety of factors including a mismatch in Oracle Home information, or corrupted listener.ora file. In this article, we will discuss troubleshooting techniques and ways to fix the ORA-12519 error.

Step-By-Step Solution

1. Check Oracle Home

The ORA-12519 error may be due to the incorrect version of the installed Oracle Home files, or the presence of mutliple Oracle Homes on your server.  To fix this issue:

  • Make sure that the version of the Oracle Home is correct – i.e. the Oracle Home of the database instance has to match the Oracle Home of the listener.ora file.
  • If there are multiple Oracle Homes installed, ensure that the right Oracle Home is set in the environment variables. This will prevent the listener.ora file from being picked up from the wrong Oracle Home.

2. Check the Listener.ora File

The listener.ora file must be present and correct in the Oracle Home directory. Oracle Listener must also be properly configured in order to start the listener. If the file is corrupted or not present on the server, then create it manually and ensure that it contains valid entries.

3. Troubleshoot Network Connectivity

If the above steps do not resolve the issue, there may be a problem with the network connectivity. Check the server for any network-related issues and ensure that the proper ports are open. Also, try running the netca utility to re-configure the listener.

4. Check Server Logs

If all else fails, check the server logs for any additional information that may point to the root cause of the error. This may provide clues on where to look for further troubleshooting.


What is ORA-12519?

ORA-12519 is an Oracle Database error which indicates that there is a problem connecting to the database instance.

What causes ORA-12519 error to appear?

ORA-12519 error can occur when the Oracle Home information is incorrect, the listener.ora file is corrupted, or there is an issue with the server's network connectivity.

How do I fix ORA-12519 error?

To fix ORA-12519 error, check the Oracle Home information, ensure that there is a valid listener.ora file, troubleshoot network connectivity, and check the server logs for additional clues.


Troubleshooting ORA-12519 ERRROR

Fixing ORA-12519 Error

ORA-12519: TNS: No Appropriate Service Handler Found

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